SBMM has always been there, it's just to what degree. I play enough crucible that I can literally feel when tweaks are made. How much do you know about statistics? I'm going to make assumptions that you know some of the basics than come up with a poor analogy... Lets assume the peak of a bellcurve of the player skill population peaks at 1000 (just an arbitrary number). SBMM determines the range of players you're able to match against. So with CBMM, anything goes...you can fight someone who hits a 0 on the skill rating, but you can also fight someone who is the best in the world...assuming they have a good connection with you, and queue for that same period of time. But with SBMM it limits the search parameters. Those parameters (or limits)could (and do) get changed rather frequently depending on player population. IE: If I'm a 1200 rated player, with SBMM, Bungie can have it set so that range of skill I can face ranges from 1000-1400. Or with heavy SBMM they can make it from 1100-1300. As you can see, the more the SBMM you have, the smaller the pool of players you can queue against....but you're less likely to face opponents that are significantly better than you, or ones that are significantly worse. So yes, there was SBMM in year 1, but it left those parameters to be pretty relaxed. Instead, they focused more on averaging out the teams (even though they still do that now). For example, if you had 3 900 rated players, 2 1400 rated players, and 6 1000 rated players, they would try and average it out so that the teams ''skill averages'' were about equal. They didn't just toss the 2 1400 rated players in the same group. Now, SBMM would work in theory with P2P if we had a massive amount of people playing the exact same crucible modes all the time. As you can see, by tightening up the SBMM parameters, you're only allowing players to be queued against a very specific group of other players...which leads to people being queued against people across continents if the population of players in that bracket is low. That's why you see an initial ''tightening'' or ''adjustments'' of SBMM after patches are applied. The population of the game increases, so Bungie responds by making the lobbies tighter to isolate the skill gaps because that population is more likely to have games with ''good connections''. The opposite holds true too. As more and more people move away from the game, the tighter restrictions they have on SBMM becomes a problem, and they'll start to ease up on it so that players can get ''good connections''. SBMM has two main variables that can influence how much it's implemented: Population of people playing the game, and what Bungie defines as ''acceptable latency, or lag'''. Year 1 had significantly more of a ''hands off approach'' in terms of adjusting those parameters. They kept things fairly open to not worry so much about population fluctuations, and depended more on averaging out the teams skill ratings.